Non-Nuclear Methods for Compaction Control of Unbound Materials

Overview or NCHRP Synthesis 456 – Munir Nazzal

Indiana Stiffness/Strength-based Compaction Control Specs – Nayyar Siddiki

Compaction Control Today and Anticipating the Future – John Siekmeier

Related Efforts

NCHRP Project 10-84 – Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate • Research Results Digest 391

TPF Project 5 (285) – Standardizing LWD Measurements for QA and Modulus Determination in Unbound Bases and Subgrades

Munir D. Nazzal, Ph.D., P.E. Associate Professor

Department of Civil Engineering Ohio University

Results of NCHRP Synthesis Report 456 On Compaction Control Of Geo-Materials

Outline

Introduction Overview of NCHRP Synthesis 456 Review of DOTs Compaction Control Specifications Non-nuclear Density Devices Devices for In Situ Stiffness/Strength Measurement Stiffness/Strength Based Specifications Conclusions

Introduction Compaction is the process by which soil particles are rearranged

and packed together to: Improve stiffness and strength Reduce excessive settlement Decrease the susceptibility of to environmental changes,

especially those caused by frost heave, swelling, or shrinkage

Proper compaction of unbound materials is one of the most critical components in the construction of unbound layer to ensure their adequate performance, durability, and stability.

DOTs assess the quality of compaction by comparing their field density to a target dry density value typically determined by conducting a specified laboratory standard compaction test.

Introduction The nuclear density gauge (NDG) is the

device used by most state DOTs for measuring the field density of compacted layers of unbound materials.

This device contains radioactive materials that can be hazardous to the health and well-being of the operators.

It entails intense handling, storage, calibration, maintenance, and transportation regulations.

The costs associated with owning, operating, licensing, transporting and maintaining NDG can be also prohibitive.

Item Cost* Cost of nuclear gauge $6,950

Radiation safety & Certification Class $750

Safety training $179 HAZMAT certification $99

RSO training $395 TLD Badge monitoring $140/year

Maintenance & Recalibration $500/year Leak test $15 Shipping $120

Radioactive Materials License $1,600 License Renewal $1500/year

Reciprocity $750 *Cho et al. (2011)

Introduction Compaction control based on density presents several challenges: From inspectors perspective : Target density value is determined using a very small sample Test methods to determine target density do not accurately

represent the compaction energy levels applied in the field From the design and performance perspective: The main purpose of compaction is to improve their engineering

properties, not only their density. The key functional properties of unbound layers are their stiffness

and strength, which are typically used in the design of different transportation structures

Consequently, there is currently a missing link between the design and compaction quality control processes.

Review current state of practice for compaction control of geo-materials.

Summarize all information on the various non-nuclear devices and methods used for compaction control of geo-materials based on: Density measurement stiffness/strength-related properties

Review of stiffness/strength-based specifications that have been developed and implemented by state DOTs for compaction control to geo-materials

NCHRP Synthesis 456 Overview

NCHRP Synthesis 456 Overview Review all published reports focusing on compaction control of

unbound materials Review all DOTs construction specification books and manuals. Conduct survey questionnaire Conduct interviews with selected DOTs

Response received No response received

Review of DOTs Compaction

Control Specifications

Compaction Control Specifications Review of DOTs Compaction Control Practices of Geo-Materials

(8)

(34)

(20)

(10) (9)

(31)

(21)

(11) (9)

(34)

(27)

(7) 19.5%

82.9%

48.8%

24.4% 22.0%

75.6%

51.2%

26.8% 22.0%

82.9%

65.9%

17.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5

10

15

20

25

30

35

40

Minimum averagerelative compaction

values

Individual relativecompaction values

Moisture contentwithin limits

Other

Perc

enta

ge o

f Sur

vey

Res

pond

ents

Num

ber

of S

urve

y R

espo

nden

ts

BaseCompacted SubgradeEmbankment

Target Density Value Selection 1. Impact Compaction Laboratory

Methods Are the most commonly used to determine

the target field density value. ASTM D 698 or AASHTO T 99

(standard effort)&ASTM D 1557 or AASHTO T 180 (modified effort)

Do not accurately represent the compaction energy levels currently applied in the field

Can only be conducted on materials below grain size 3/4 inch If the particles in excess of this size is included, corrections

need to be applied using AASHTO T224. This correction cannot be applied if the tested materials have

more than 30% by mass of its particles larger than 3/4 inch.

Target Density Value Selection 2. Static Compaction Laboratory Method Has not been widely used since static pressure was not found

to be effective in compacting granular materials Currently there is no standard procedure

3. Vibratory Compaction Laboratory Method This method was reported to produce consistently higher

maximum densities for granular materials than the impact compaction method and also better replicates of field.

Some studies indicated that it can be effective in cohesive soils if compacted at low frequencies.

Only two state DOTs (Kansas and Alabama) reported the use of this method for unbound aggregate materials.

Target Density Value Selection 4. Gyratory Compaction Laboratory Method Introduced by the U.S. Army Corps of Engineers. Involves applying a controlled normal force to both the top

and bottom of the sample at a constant gyration rate. Currently, there are no standard values available Different gyratory compaction parameters were used in

previous studies.

Study Vertical Stress (kPa)

Gyration angle

No. of Gyration

s Soil type

Smith (2000) 1380 1.0 30-40 Crushed stone Ping (2003) 2000 1.25 90 Fine sand

Kim and Labuz (2006) 6000 1.25 50 Recycled material

White et al. (2007) 6000 1.25 50 Granular and cohesive soils

Target Density Value Selection 5. Test Strip Method Used to determine the maximum target density value as well

as the roller type, pattern, and number of passes. Test sections are typically constructed every 1500 to 4000

yd3 or where the compacted material changes significantly. Field density and moisture measurements are obtained at

three or more randomly selected locations after each pass until no significant increase in density is observed. The average final density is used as the maximum target density.

Usually agencies specify that lifts must be compacted to a certain percentage of this maximum density.

Several DOTs have specifications for using control strips in their compaction control procedures for geo-materials.

NON- NUCLEAR DEVICES FOR DENSITY MEASUREMENTS

OF GEO-MATERIALS

Non-Nuclear Density Devices

There is consensus among respondents for not recommending using any of the available non-nuclear density devices

(6)

(12)

(5)

(29)

(2) 15%

29%

12%

71%

5% 0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5

10

15

20

25

30

35

40

45

MDI EDG SDG None Other

Perc

enta

ge o

f Sur

vey

Res

pond

ents

Num

ber

of S

urve

y R

espo

nden

ts

Number of Respondents that Used or Evaluated Non-nuclear Density Devices

Electrical Density Gauge (EDG) EDG uses high radio frequency waves to measure

the density and moisture content of soils. The device works by transmitting high radio

frequency waves through the four probes that are driven into the soil in a square formation.

The EDG analyzes the transmitted radio frequency to determine dry density and moisture content measurements.

Test Method Electrical Standard None

Measurement γd, w

Calibration of Device Field calibration using direct measurement of γd, w

Portability Medium Durability Good

Operator skill Moderate Ease of use-Training Difficult

Initial Cost $9,300 Data Storage Yes Repeatability Mixed Results

Accuracy Mixed Results

Main Limitations -Complex and time consuming -NDG is required for calibration -Cannot test highly plastic clay

Moisture Density Indicator (MDI)

The MDI utilizes Time Domain Reflectometry (TDR) to measure the dry unit weight and moisture content of soils.

The MDI works by sending an electromagnetic wave pulse through the four probes that are driven into the soil.

Test Method Electrical Standard D 6780

Measurement γd, w Calibration of Device Laboratory testing in Proctor mold

Portability Medium Durability Good

Operator skill Moderate Ease of use-Training Difficult

Initial Cost $6,000 Data Storage Yes Repeatability Good

Accuracy Mixed Results GPS No

Main Limitations -Complex and time consuming -Cannot test highly plastic clay.

Soil Density Gauge (SDG) SDG is a self-contained unit that uses

Electromagnetic Impedance Spectroscopy (EIS) to measure the density and moisture content of various unbound materials.

the SDG measurement is done through a non-contacting sensor that consists of a central ring and an outer ring.

The central ring generates and transmits a radio frequency-range electromagnetic field into the soil.

The response to that field is received by the outer ring and is used to measure the dielectric properties of the tested soil matrix.

Test Method Electrical Standard None

Measurement γd, w Calibration of

Device Field calibration using direct

measurement of γd, w Portability Good Durability Good

Operator skill Extensive Ease of use-

Training Difficult

Initial Cost $10,000 Data Storage Yes Repeatability *

Accuracy * GPS Yes

Main Limitations -Extensive operator training

Methods for In Situ Stiffness/Strength Measurement

In Situ Stiffness/Strength Devices

Spot In-situ Tests

Continuous compaction control

Intelligent compaction

In Situ Stiffness/Strength Devices

In Situ Stiffness/Strength Devices

(6)

(19) (20)

(13)

(1) (0) (1)

(6)

(15)

15%

46% 49%

32%

2% 0% 2%

15%

37%

0%10%20%30%40%50%60%70%80%90%100%

0

5

10

15

20

25

30

35

40

45

CleggHammer

GeoGauge DCP LWD PSPA SCS BCD Other None

Perc

enta

ge o

f Sur

vey

Res

pond

ents

Num

ber

of S

urve

y R

espo

nden

ts

Number of respondents that used or evaluated in situ stiffness/strength devices for compaction control

BCD: Briaud Compaction Device DCP: Dynamic Cone Penetrometer CH: Clegg Hammer LWD: Light Weight Deflectometer PSPA: Portable Seismic Property Analyzer SCS: Soil Compaction Supervisor

Dynamic Cone Penetrometer (DCP)

The DCP was initially developed in South Africa for in-situ evaluation of pavement

Conducted by dropping a 8-kg weight from 575-mm height and recording the penetration for each blow.

The DCP Penetration Index (DPI) is used to assess strength properties of tested layer.

ASTM Standard D6951 Measurement DPI Moisture Measurement No Calibration of Device None Portability Good Durability Good Ease of use/Training Easy-minimal Initial Cost $1,000 Influence Depth (inch) 48 Repeatability Good

Main Strengths

- Simple, quick for shallow depth - Economical -Assess up to 4ft thick layers -Strong correlation with CBR & Mr -Used in Many DOTs

Main Limitations -May require 2 persons -Max. allowed particle size is 2 in. -Deeper testing can take up to 15 min

GeoGauge

Consist of a shaker that vibrates the foot, and sensors that measure the applied load and deflection

Generate a very small dynamic force at frequencies of 100 to 196 Hz

Applied load estimated to be 10 N Vertical displacement less than 1.3

x 10 -6 m. 2(1 )

(1.77 )SG SGE H KRν−

=

ASTM Standard D6758 Measurement Modulus Moisture Measurement No Calibration of Device Calibration plate Portability Good Durability Good Ease of use/Training Easy-minimal Initial Cost $5,000 - $5,500 Data Storage Yes Influence Depth (inch) 5-8 Repeatability Fair GPS Yes

Main Strengths -Simple, quick and non-intrusive - good portability and durability

Main Limitations -Extremely sensitive to seating conditions -Inconsistencies in testing data -Unfavorable findings by several DOT’s

Light Falling Weight Deflectometer (LWD)

It consists of a loading device (10 kg drop weight), a loading plate, and one center geophone sensor to measure the center surface deflection

The falling weight impact a spring to produce a load pulse of 15-20 milliseconds

Load range: 1-15 kN

2(1 )LWD

c

v RE σδ

− ×=

ASTM Standard E2583 Measurement Modulus Moisture Measurement No Calibration of Device Required Portability Medium Durability Good Ease of use/Training Moderate Initial Cost $8,000 - $15,000 Data Storage Yes Influence Depth (inch) 11 (1-1.5D)* Repeatability Fair GPS No

Main Strengths -Quick - Measure wide range modulus values -Not influenced by aggregate size

Main Limitations - High variability in weak soft soils -May require 2 persons

Agencies Experience with Devices

DCP GeoGauge LWD

Rec

omm

enda

tion

(11)65%

(2)12%

(4)23%

YesNoI don't Know

(8)42%

(11)58%

YesNoI don't Know

(9)69%

(4)31%

YesNoI don't Know

Intelligent Compaction

(2)

(10) (11) (13) (17)

5%

24% 27% 32%

42%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5

10

15

20

25

30

35

40

45

Implementedin fieldprojects

Evaluated inresearch

studies only

Demonstratedits usage

Plan to use inthe future

Not used norevaluated

Perc

enta

ge o

f Sur

vey

Res

pond

ents

Num

ber

of S

urve

y R

espo

nden

ts Extent of agencies usage of intelligent compaction

Stiffness/Strength Based Specifications

Stiffness/Strength Based Specifications

(2) (6)

(19)

(9) (5)

5% 15%

46%

22% 12%

0%10%20%30%40%50%60%70%80%90%100%

05

1015202530354045

Interested andhave already

implemented it

Interested andwill implement

it

Interested buthave not

implemented it

Not Interested Other (pleasespecify)

Perc

enta

ge o

f Sur

vey

Res

pond

ents

Num

ber

of S

urve

y R

espo

nden

ts

Level of implementation of stiffness/strength based specifications for compaction control

Stiffness/Strength Based Specifications Only a few state DOTs have developed compaction control

specifications for unbound materials that are based on in situ stiffness/strength measurements

State DOT Specifications links

Minnesota

DCP specification: http://www.dot.state.mn.us/materials/gbmodpi.html LWD specification: http://www.dot.state.mn.us/materials/gblwd.html

Indiana

DCP specification: http://www.state.in.us/indot/files/Fieldtesting.pdf LWD specification: http://www.in.gov/indot/div/mt/itm/pubs/508_testing.pdf

Missouri http://www.modot.org/business/standards_and_specs/Sec0304.pdf

Illinois http://www.dot.il.gov/bridges/pdf/S-33%20Class%20Reference%20Guide.pdf

MnDOT Stiffness/Strength Based Specifications DCP is used for base aggregates, granular subgrade, and

edge drain trench filter aggregates. Maximum allowable DCP penetration is found using:

MC: the moisture content at the time of testing, GN: Grading Number, calculated GN = [25 mm+19mm+9.5mm+4.75mm+ 2.00mm+425µm +75µm]/100

DPImax(mm/blow)=4.76xGN+1.68MC-14.4

GN In Situ Moisture (% by dry weight)

Maximum Allowable

Seating (mm)

Maximum Allowable DPI

(mm/blow)

3.1-3.5

< 4.0 40 10 4.1-6.0 40 10 6.1-8.0 40 13 8.1-10.0 40 16

3.6-4.0 < 4.0 40 10

MnDOT Stiffness/Strength Based Specifications LWD is used for granular as well as fine grained soils

Grading Number GN

Moisture Content (%)

Estimated LWD Modulus Estimated LWD

Deflection Zorn (mm)

Keros/Dynatest (MPa) Zorn

(MPa)

3.1 – 3.5 5 -7 120 80 0.38 100 100 67 0.45 75 75 50 0.6

3.6 – 4.0 5 -7 120 80 0.38 80 80 53 0.56 63 63 42 0.71

Plastic Limit

Estimated Optimum Moisture

Field Moisture as a

Percent of Optimum Moisture

DCP Estimated

DPI at Field Moisture

Zorn Deflection Estimated at

Field Moisture minimum

Zorn Deflection

Estimated at Field

Moisture maximum

15-19 10-14

70-74 12 0.5 1.1 75-79 14 0.6 1.2 80-84 16 0.7 1.3 85-89 18 0.8 1.4 90-94 22 1 1.6

Gra

nula

r So

ils

Fine

gra

ined

Soi

l

INDOT Stiffness/Strength Based Specifications

Specifications

DCP clay, silt, or sand aggregate sizes greater than ¾

inch, coarse aggregate sizes No. 43, No. 53, and No. 73, and structural backfill sizes 1& 2 inch

LWD

NDCPreq= 59exp(-0.12wcopt)

granular soils with aggregate sizes smaller than ¾ inch, and structural backfill sizes 1 inch, 1/2 inch, No. 4 and No. 30.

Target LWD deflection is determined by preforming LWD with roller passes on a test section 100 ft long

Conclusions The majority of DOTs use field density measurements obtained

by the nuclear density gauge for compaction control of various types of geo-materials.

DOTs overall satisfaction with non-nuclear density devices is so low that none of them recommended their use. More difficult to operate and require longer testing time

than nuclear density gauge DCP, GeoGauge, and LWD are the most evaluated devices by

DOTs among all in situ tests stiffness/strength devices. The DCP and LWD have been implemented by some DOTs in

the field for compaction control of geo-materials. GeoGauge measurement was found to be very sensitive to the

seating procedure and to the stiffness of the top two inches of the tested soil layer, which significantly affected its reliability.

Conclusions The influence depth differs between the various in situ devices. Some devices have shallow depths that may not allow them

to assess the properties of the entire lift. The zone of influence of some devices might exceed the lift

thickness and it, thus providing a composite value of two layers rather than solely the tested layer.

There is not one single in situ test device that can assess all types of geo-materials. The BCD, DCP, LWD and SCS may not be suitable for very

soft, fine-grained soils. In general, no strong correlation was found between in situ

stiffness/strength measurements and in-place density, as this relationship continuously changes with moisture content.

Conclusions The majority of transportation agencies are interested in

implementing stiffness/strength based specifications for compaction control of geo-materials.

Only Indiana and Minnesota have widely implemented stiffness/strength based specifications, and both states use the DCP and LWD in those specifications

Most research and implementation projects that were conducted on the use of continuous and intelligent compaction reported considerable success with and numerous benefits of these technologies.

However, currently, only three state DOTs (Indiana, Minnesota, and Texas), have IC specifications.

Non-Nuclear Methods for Compaction Control of Unbound Materials

Nayyar Siddiki, M.S., P.E. Geotech. Construction and Tech. Support Engineer

INDOT, Office of Geotechnical Services December 3, 2015

Office: 317 610-7251 X 228 Cell: 317 903-0957

nsiddiki@indot.in.gov

Outline Historical Background Use of Resilient Modulus in lieu of CBR in subgrade design Motivation Behind the change in Construction Specifications Light Weight Deflectometer Device and Test Method Construction Specifications Limitations and Repeatability

Outline (Cont’d.)

Dynamic Cone Penetrometer Device and Test Method Construction Specifications Limitations

Indiana Test Methods Questions

FHWA/IN/JHRP-92/23, Subgrade Resilient Modulus for Pavement Design and Evaluation, Woojin Lee, Nihal C. Bohra, Adolph G. Altschaeffl, and Thomas D. White, HPR-2032 FHWA/IN/JTRP-98/02-1, Implementation of Subgrade Resilient Modulus for Pavement: Laboratory Procedures Manual (2 volumes), A. G. Altschaeffl, Ross A. Duckworth, and M. K. Clough, SPR-2134 FHWA/IN/JTRP-98/02-2, Implementation of Subgrade Resilient Modulus for Pavement (2 volumes), A. G. Altschaeffl, Ross A. Duckworth, and M. K. Clough, SPR-2134 FHWA/IN/JTRP-2004/35, Non-Destructive Estimation of Pavement Thickness, Structural Number and Subgrade Resilience along INDOT Highways, Samy Noureldin, Karen Zhu, Dwayne Authur Harris, and Shuo Li, SPR-2408 FHWA/IN/JTRP-2005/23, Simplification of Resilient Modulus Testing for Subgrades, Daehyeon Kim and Nayyar Zia Siddiki, SPR-2633

Joint Transportation Research Projects, JTRP Studies

1998, JTRP Technical Report Series Cone Penetration Test to Assess the Mechanical Properties of Subgrade Soils 2010, FHWA/IN/JTRP-2010/27 SPR- 3009 Use of Dynamic Cone Penetration And Clegg Hammer Tests For Quality Control of Roadway Compaction and Construction JTRP & In-House Research 2014, FHWA/IN/JTRP SPR-3537 QA/QC of Subgrade and Embankment Construction 2014, JTRP SPR#3651 Developing Statistical Limits for using the Light Weight Deflectometer, LWD in Construction Quality Assurance

Research Studies Completed to Improve the Construction JTRP & In-House Research

Subgrade Type and Mr Recommendations During Design Phase

Type of Work Traffic Subgrade Length Subgrade Type and Description

Mr Value 1.25 times Mr @ σ1=6psi and σ3=2psi

at OMC

New Road, Road Reconstruction and >8 feet Widening

*VPD ≥ 1,000 or Truck ≥ 5 % > 800 feet

Type-IB 14 inches-chemical Soil Modification

Granular Soils- Clay < 20%, PI < 10 - Cement

Cohesive Soils- Clay > 20 %, PI > 10 -Lime

Up to Mr - 9,500 psi

New Road, Road Reconstruction and <8 feet Widening

•VPD ≥ 1,000 or Truck ≥ 5 % _

Type IC Excavation and replacement with 12 inches

Aggregates

Up to Mr - 9,500 psi

New Pavement or Reconstruction

High water/ urban area, shallow utilities or others _

Type IV 12 inches Aggregates w/Geogrid Type IB &

woven Geotextile if needed

Up to Mr - 9,500 psi

New Road, Road Reconstruction

*VPD ≤ 1,000 or Truck ≤ 5 % _ Type I

24 inches Strength/density and Moisture Control Up to

Mr - 7500 psi

* Vehicle per day

INDOT adopted Resilient Modulus (Mr) since 2002 and following recommendations are included in Geotechnical Report for designing the pavement.

Subgrade Type Resilient Modulus of prepared subgrade Resilient Modulus of foundation soils

AASHTO Classification

Water Table

Measure fundamental properties of material (strength, modulus, etc.)

Delineate the poor to good compaction in short

time Simple enough to train and easy to perform with

no electronics Precise enough to accept with confidence Safety issues (nuclear gauge handling)

Motivation Behind the Change in Construction Specifications

Clegg Hammer (Hammer weight, 10kg).

Moisture Probe Microwave Oven Moisture Analyzer

Dynamic Cone Penetrometer Light Weight Deflectometer

Equipments Evaluated Devices Evaluated

Light Weight Deflectometer - LWD

Indiana Test Method ITM-508

Select site and prepare surface. LWD plate should not translate laterally. Perform three seating (1st, 2nd and 3rd) drops from the

fixed height Record the average of 4th, 5th and 6th drops and the

test is complete. Deflection > 0.03 mm for any two consecutive drops

warrants compaction.

LWD Test Procedure, ITM 508

The maximum allowable deflection for #53 aggregate will be as follows or determined by the test section. Mate

Lime Modified Soil 0.30 Cement Modified Soil 0.27 Aggregates over Lime Modified Soil 0.30 Aggregates over Cement Modified Soil 0.27

Materials not included in the table need a test section.

Compaction Acceptance with LWD 203-R-628

Material Type Maximum Allowable Deflection (mm)

A fully legally loaded tri-axle dump truck. ( About 70,000 lbs.)

Proofrolling of Chemically Modified Soil

Sec. 207 and 300 requires proofrolling prior to placing next layer

100 ft

X

X

X

X X

X

X

X

X

X

½ Width of Placement

Compaction Acceptance with LWD, 203-R-628 A Test Section Layout

Test sections shall be constructed in accordance with ITM 514.

Test Section Size: 100 X 20 feet Aggregate Moisture: -3% of OMC and OMC Compacted Lift Thickness: 6 inches

Test Section Requirements, ITM-514 1. Proofroll and construct a lift.

2. Test 10 random locations and take the average. 3. Perform additional compaction. Retest previous test locations and take the average. 4. Subtract the average deflection of step 3 from step 2. 5. If the difference in step 4 is <0.02 mm. Test section is complete

ITM-514 Cont’d. 6. If the difference is >0.02 mm, additional compaction is required. 7. Step 3 is the maximum allowable deflection and used for the remaining project.

Compaction Acceptance with LWD, 203-R-628 Gradation and OMC on aggregates by (AASHTO

T11,T27 and T99). Moisture: -3% of OMC and OMC Testing Frequency 3 Tests/1,400 cyd of chemically modified soils.

3 Tests/800 t for compacted aggregates at random

station. One moisture test / day in accordance with AASHTO

T 255.

Limitation

The aggregates larger than 1.5 in. shall not be over 15% in testing location.

The testing location shall not exceed 5% inclination.

The testing location shall not be frozen.

Test shall not be executed when deflection measurements are less than 0.2 mm.

LWD test is questionable in case of shallow ground water (2 feet) or soil with high moisture content.

LWD Repeatability Procedure

The Office of Material Management will establish the repeatability of lightweight Deflectometer (LWD) deflection measurements under defined conditions.

Repeatability testing will be performed: Immediately upon receipt of a newly purchased device Immediately after full calibration After significant repair Annually When measurements are no longer repeatable or questionable

Projects completed 118 Test Performed 2011

Projects and Tests Completed in 2014

Dynamic Cone Penetrometer

Indiana Test Method ITM-509

Soil type Correlation R2

Penetration

depth

(inches)

Range of

applicability

Coarse- grained

soils

Natural Blow Count= 0.17 x OMC2 -5.94 x OMC + 60 0.95 0-to-12 8<OMC%<13

Manufactured Blow Count= 4.03 x ln (Cu) +2.64 0.99 0-to-12 3.0<Cu<6.0

Fine-grained soils

Blow Count= 13.03 x e-23 x PI + 8.05 x e-0.005x PI

0.99 0-to-6

8 > PI% Blow Count= 22.11 x e-0.23 x PI +13.04 x e -0.012 x PI

0.98 6-to-12

Based on the research (QA/QC of Subgrade and Embankment Construction) the following relationships were developed

Section 203.23

Test Pad Construction Sieve Analysis………AASHTO T-88, T-89/or ASTM D-1140 Atterberg Limits ………… AASHTO T-90

Moisture –Density ……… AASHTO T-99

Loss on Ignition……………AASHTO T-267 Ca/Mg Carbonate………… ITM-507* Sulfate test ITM 510 *Not required when presence of shells in soil or density <105 lbs.

The following laboratory tests are required during construction:

Section 203.23 Cont’d.

More than 1800 tests performed in the laboratory, grouped in three categories on the basis of Maximum Dry Density and other parameters. Cohesive Soil: Soil is cohesive when >35% passing No.200 sieve and categorize as:

Soil Types

Clay - Max. dry density ≤ 114 pcf Silty - Max. dry density ≥ 114 pcf and ≤ 120 pcf Sandy- Max. dry density > 120 pcf

Granular Soil: Soil is non cohesive when <35 % passing No. 200 sieve.

Embankment other than Rock, with Strength or Density Control, Sec. 203.23

Soil Type Moisture Compaction Range

Clay (<105 lb/cu ft) -2 to + 2% of optimum moisture content

Clay (105-114 lb/cu ft) -2 to + 1% of optimum moisture content

Silty and Sandy (>114 lb/cu ft) -3% of optimum moisture content

and optimum

Granular 5 to 8%

Moisture range for all soil types are as follows:

Moisture Range for Compaction Section 203.23 Cont’d.

Silty , Sandy & Granular Soils

6”

6”

6” 3rd Lift

6”

6”

6”

1st Lift

Dynamic Cone Penetrometer Testing

Dynamic Cone Penetrometer (DCP)

Clayey Soils

6”

6”

6”

2nd Lift

3rd Lift

6”

6”

6”

1st Lift

2nd Lift

3rd Lift

2nd Lift

6 inches

8 inches

8 inches

14 inches

17 blows or more for the first 6 inches

16 blows or more for the next 8 inches

20 blows or more for the first 8 inches

Chemically Modified Soils

DCP blow counts for the chemically modified soils

Frequency of Testing 3 Random test / 2000 cyd of compacted soil.

Moisture test at every 4 hrs for clayey soils.

Moisture test once per day for other type of soils. Note: The moisture sample should represent the entire lift. Additional moisture tests may be required if there is an obvious visual change in moisture

Section 203.23 Cont’d.

When the soil type changes during construction: One Point Proctor shall be performed to identify the soil type and revised DCP blow counts in accordance with the ITM 512-15T

Motive behind performing One Point Proctor

To determine the following properties at the project:

Optimum Moisture Content of the blended soils

Maximum Dry Density and the use of ITM 512 Charts

Density based soils classification

Adjusted Optimum Moisture and DCP blow counts

One Point Proctor

134 pcf

119 pcf

+1%

127 pcf MC 12%

MC 12%

134 pcf

Example-1

MDD=119 pcf OMC= 12%

One Point Proctor ITM - 512

-Data not to be used with Granular Soils. -Plot based on data acquired from July 1965 to January 1969 by Soils Department . -Moisture must be between -3% and +1% for a valid Maximum Wet Density -These charts are an alternative to the Family of Curves and may be used in accordance with ITM-512 -Revised 4/4/14

Field Criteria for DCP Blow Counts

The DCP is portable, easy to operate, and requires no electronics. It takes couple of minutes to learn the test.

It is an effective tool to identify weak layers when penetration rates are plotted vs. depth.

Improve inspector safety.

Directly related to design.

Increase compaction uniformity.

Increase productivity due to less time per test.

Improve documentation and reporting.

Conclusion

INDOT Inventory of LWD and DCP Devices

LWD (ZORN) & DCP (KESSLER)

Available With No's of LWD No's of DCP

INDOT 60 200 +

CONSULTANTS 10 30

Equipment Inventory

Device Estimated Tests Per 8-hr Day

Daily Employee

Rate

Daily Equipment

Rate

Daily Charge

Cost Per Test

(Approx.)

Est. Device Price

NDG including 1-Point Proctor 18 $336.00 $35.00 $371.00 $20.60 $ 8,000.00-

$12,000.00

DCP 32 $336.00 $ 3.00 $339.00 $10.00 $ 1,000.00-

$ 1,300.00

LWD 72 $336.00 $14.00 $350.00 $ 5.00 $ 7,500.00-

$ 1,2000.00

Cost Comparison Among NDG, DCP, and LWD

Other Costs: NDG - Training: Safety and Maintenance DCP - None LWD- Calibration and Verification

Comparison Cost / Test With Different Devices

Material Types Lab. Testing

Field Testing Max.

DD & OMC (ITM 512)

DCP (ITM 509)

Sand Cone (AASHTO

T191)

Moisture Test LWD (ITM 508) (ITM 506) AASHTO

T255

Cohesive Soils AASHTO T 99 (Method A) X X X X N/A N/A

Granular Soils

AASHTO T 99 (Method A or C) N/A N/A X X N/A X

(Soils with aggregate retained on the 3/4 in., structural backfill size 2 in. and 1 1/2 in., and b borrow with a similar gradation) Granular Soils

AASHTO T 99 (Method A or C) N/A X X X N/A N/A

(Soils with 100% passing 3/4 in., structural backfill sizes 1 in., 1/2 in. No 4, No. 30, and b borrow with a similar gradation) Coarse Aggregates

AASHTO T 99 (Method A or C)

N/A N/A X N/A X X (No. 43, 53, and 73) Coarse Aggregates Field Testing is not required. Compaction in accordance with applicable specification. (No. 5, 8, 9, 11 or 12)

Chemical Modified Soils AASHTO T 99 Performed by the Contractor

N/A X N/A *X N/A X

N/A Not Applicable *X No Microwave Testing No Probe Testing

INDOT Compaction Requirements

ITM No. 506-15T Field Determination of Moisture Content of Soil ITM No. 508-12T Field Determination of Deflection Using Light Weight Deflectometer ITM No. 509-15P Field Determination of Strength Using Dynamic Cone Penetrometer ITM No. 512-15T Field Determination of Maximum Dry Density and Optimum Moisture Content of Soil (AASHTO T272) ITM No. 514-15T Test Sections for Aggregates and Recycled Materials

ITM for Compaction Acceptance

Compaction Control Today and Anticipating the Future

NCHRP Synthesis 456 “Non-Nuclear Methods for Compaction Control

of Unbound Materials”

John Siekmeier P.E. M.ASCE

Why would we replace a density-based specification with a

modulus-based specification? Road foundations are important. Poor performance has consequences. Testing has NOT “always been done this way.” Building financially effective highways for the

21st century requires 21st century technology.

Road Foundations are Important

surface measure subsurface measure

Poor Performance has Consequences

Unable to maintain our public assets. Waste labor, energy, and natural resources. Public confidence reduced. New investments (higher gas tax) difficult.

Ralph Proctor reminds us.

photo courtesy of Dr. J. David Rogers University of Missouri-Rolla

■ Strength is not achieved by density alone.

■ Optimum moisture is for compaction.

■ Need to avoid rutting during construction.

Ralph Proctor, 1945, Trans 110, ASCE

“Methods for hand compaction, such as dropping various weight tampers from different heights and mechanical tampers, were tried and discarded.”

“No use is made of the actual peak dry weight.” “The measure of soil compaction used is the

indicated saturation penetration resistance.”

Proctor Penetrometer

Photo courtesy of Humboldt

Mechanistic Empirical Pavement Design

Provides the framework for using performance based material properties

Free design software available http://www.dot.state.mn.us/app/mnpave/index.html

Just Google “MnPAVE”

Estimated Target Values

Verifies pavement design inputs Empowers inspector

with useful measures Creates as-built

construction record

Light Weight Deflectometer Links Design to Construction

Design, Construction and Performance Pavement Design Construction Quality Control

Construction Quality Assurance Performance Measurement

Action Items and Future Work

Continue participation on national project teams. TPF (5)285 Standardized LWD Measurements for QA

Inspector certification training includes LWD. Educate designers, opportunity to optimize design. Enhance LWD and DCP target value prediction. Specification to include design-based LWD targets. Further development of moisture/suction field test.

Thank you. Questions?